package com.usian.admin.gateway.filter;

import com.usian.admin.gateway.util.AppJwtUtil;
import io.jsonwebtoken.Claims;
import org.apache.commons.lang3.StringUtils;
import org.springframework.cloud.gateway.filter.GatewayFilterChain;
import org.springframework.cloud.gateway.filter.GlobalFilter;
import org.springframework.core.Ordered;
import org.springframework.http.HttpHeaders;
import org.springframework.http.HttpStatus;
import org.springframework.http.server.reactive.ServerHttpRequest;
import org.springframework.http.server.reactive.ServerHttpResponse;
import org.springframework.stereotype.Component;
import org.springframework.web.server.ServerWebExchange;
import reactor.core.publisher.Mono;

@Component
public class GatewayFilter implements GlobalFilter, Ordered {
    @Override
    public Mono<Void> filter(ServerWebExchange exchange, GatewayFilterChain chain) {

        //1.获取请求对象和响应对象
        ServerHttpResponse response = exchange.getResponse();
        ServerHttpRequest request = exchange.getRequest();

        //2.判断当前的请求是否为登录，如果是，直接放行
        if (request.getURI().getPath().contains("/login/in")){
            //放行
            return chain.filter(exchange);
        }

        //3.获取当前用户的请求头jwt信息
        HttpHeaders headers = request.getHeaders();
        String token = headers.getFirst("token");

        //4、判断是否有token
        if (StringUtils.isBlank(token)){

            //如果不存在，向客户端返回错误提示信息
            response.setStatusCode(HttpStatus.UNAUTHORIZED);
            return response.setComplete();
        }

        try {

            //5.如果令牌存在，解析jwt令牌，判断该令牌是否合法，如果不合法，则向客户端返回错误信息
            Claims claims = AppJwtUtil.getClaimsBody(token);
            int i = AppJwtUtil.verifyToken(claims);

            if (i==0 || i==-1){
                //5.1 合法，则向header中重新设置userId
                Integer id = (Integer) claims.get("id");
                //重新设置token到header中
                ServerHttpRequest serverHttpRequest = request.mutate().headers(httpHeaders -> {
                    httpHeaders.add("userId", id + "");
                }).build();
                exchange.mutate().request(serverHttpRequest).build();
            }

        }catch (Exception e){
            e.printStackTrace();
            //把错误信息返回给客户端
            response.setStatusCode(HttpStatus.UNAUTHORIZED);
            return response.setComplete();
        }

        return chain.filter(exchange);

    }

    @Override
    public int getOrder() {
        return 0;
    }
}
